linux-kernel - [PATCH v2] Drivers: hv: get rid of timeout in vmbus

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Date:	Mon,  6 Jun 2016 14:28:09 +0200
From:	Vitaly Kuznetsov <vkuznets@...hat.com>
To:	devel@...uxdriverproject.org
Cc:	linux-kernel@...r.kernel.org,
	Haiyang Zhang <haiyangz@...rosoft.com>,
	"K. Y. Srinivasan" <kys@...rosoft.com>
Subject: [PATCH v2] Drivers: hv: get rid of timeout in vmbus_open()

vmbus_teardown_gpadl() can result in infinite wait when it is called
on 5 second timeout in vmbus_open(). The issue is caused by the fact
that gpadl teardown operation won't ever succeed for an opened channel
and the timeout isn't always enough. As a guest, we can always trust
the host to respond to our request (and there is nothing we can do if
it doesn't).

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
- The patch is the successor of previously sent '[PATCH] Drivers: hv: fix
 infinite wait when channel open timeouts, thus v2.
- Remove the timeout completely [K. Y. Srinivasan]
---
 drivers/hv/channel.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 6a8660d..e47d37d 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -73,7 +73,6 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 	void *in, *out;
 	unsigned long flags;
 	int ret, err = 0;
-	unsigned long t;
 	struct page *page;
 
 	spin_lock_irqsave(&newchannel->lock, flags);
@@ -183,11 +182,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 		goto error1;
 	}
 
-	t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
-	if (t == 0) {
-		err = -ETIMEDOUT;
-		goto error1;
-	}
+	wait_for_completion(&open_info->waitevent);
 
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 	list_del(&open_info->msglistentry);
-- 
2.5.5